Mechanical musical instrument.



No. 893,263. PATENTED JULY 14, 1908.

R. J. PRETTIE. MECHANICAL MUSICAL INSTRUMENT.

APPLICATION FILED JUNE 28. 1907.

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A TTORN v PATENTED JULY 14, 1908. R. J. PRETTIE.

MECHANICAL MUSICAL INSTRUMENT.

APPLIGATION FILED JUNE 28. 1907.

2 SHBETS-SHEET 2.

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unrrnn srnrns rzrnnr ornror RICHARD J. PRETTIE, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO THE AEOLIAN COMPANY, A CORPORATION OF CONNECTICUT.

. MECHANICAL MUSICAL ENSTRUMENT.

Specification elf Letters Pat ent.

Patented Jul is, race.

Application filed June 28, 1907. Serial N 0. 381,192.

To all whom it may concern:

Be it'known that l, RICHARD J. Pnnr'rrn, a citizen of the United States, and resident of lVorcester, Worcester county, Massachusetts, have invented certain new and useful Improvements in Mechanical Musical Instruments, of which the following is a specification accompanied by drawings.

My invention relates to pneumatmally a'ctuated mechanical musical instruments, whether operated by pressure or suction, the particular form shown in the present application being operated by air under pressure. As is usual in instruments of this class, the airis admitted to the pneumatic key-actuating devices through a properly perforated music sheet Nhen a single bank of keys is to be operated these music sheets are provided with perforations usually fifty-eight in number 'one" from each key-actuating device. operate more than one bank of keys from music sheets of the customary width, in 00* operation with a trackerboard of the same width, in which case both the music sheet and trackerboard are provided with the requisite additional perforations. In order that this additional number of perforations in the music sheet may be used, they must be made of less area than those used when only a single bank of keys is operated, and must, it is evident, be arranged in such relation that when the single bank music sheet is used the perforations thereof will not register with. any of those provided, in the trackerboard, for the additional bank or banks of keys, It has, however, been found in practice that certain difficulties arise with an instrument arranged in the manner above described, due to the insuflicient venting of the space behind the valve controlling device, and it is the purpose of the present invention to remedy these dilliculties. l attain this purpose by the mechanism illustrated in the accompanying drawings in which Figure l is a sectional elevation showing my vent controlling apparatus arranged for use with a music sheet intended to operate two banks of keys. Fig. 2 is a similar view showing the apparatus arranged for use with a music sheet having a single set of openings. Fig. 3 is front view of the music sheet provided with two sets cf perforations, a portion .being cut away to show the trackerboard.

Fig. 4 is a front view of the apparatus when It is, however, sometimes desired to using a music sheet having a single set of per forations, to cooperate with a trackerboard having a double set of perforations.

In the drawings A designates a box or cas-,

inglforming a closed pressure chamber, to which air is admitted under pressure in the usual way. In this chamberis mountrxl trackerboard B, provided with a double set of perforations, shown as arranged in two lines in staggered relation to each other, though they may, of course, be otherwise arranged, as, for example, side by side. All that is essential is that one set of perforations shall be so arranged that the perforations in the single bank music sheet shall register with this set only and not with the perforations of the second set.

D is a music sheet arranged to he unwound and rewound over drums in the usual way, and provided with a double set of perforations, which may be either sets of holes or slots, for operating a two bank instrument, and E (Figs. 2 and 3) is a music sheet having as usual only one set of perforations. 1

Each set of holes in'the trackerboard connected by tubing F, G, to conduits H, l, in the valve boxes J. Each. of these valve boxes has a pressure chamber K, in the bot-' tom of which is a passageway-for each of series of notes in which is mounted a doubleacting valve L, carried by a diaphragm hi, the valve being arranged to either admit air from the pressure chamber K to a conduit leading to the pneumatics, or to connect such conduit N to the open air.

In practice it has been found that when the music sheet E witlrits larger openings is used, under the same pressure requisite when using the two-bank music sheet, with its comparatively small openings, that the-reisnot a sufficiently expeditious venting of the conduits l and the chambers beneath the diaphragms M- I thereforeprovidc in addition to the usual vents or bleed-openings D in such. chambers, additional bleed-op i'i -s which are opened and closed by the pivoted to the valve box. The valve ..1 pro vided with an upstanding piece R, to thcend of which is secured one end of a spring S hav-- ing its other end secured to the valve box. Loosely connected to theend of the upstanding piece ll,is a screw-threaded rod T, having a nut U, against which the piece it bears. At its other end the rod T is eccentrically connected to a rock-shaft V. passing through llO ' the side ofthe trackerboard casing A, and

having at its inner end a finger-piece W. The valve Q is held open against the tension of the spring by the friction of the rock-shaft in its bearings, or a catch (notshown) may be provided for the .fingeriece W. The various chambers, as that in ox A'and the chambers K in the valve boxes, are supplied with air pressure in the usual way and of course the invention can be ap lied where tension instead of pressure is user In 0 eration, when it is desired to use a multip e bank music sheet, the valve is moved, as shown in Fig. 1, toclose the a di tional bleed-opening P. When itis desired to use the music sheet E, the valve is raised by shifting the finger-piece, thus furnishing an additional vent through the bleed-opening 'P, thetwo openings serving to promptly and efliciently re ieve any residual pressure in the tubes G and conduits I, thus enabling the valve M to operate with the requisite speed.

I do not Wish to be limited to the use of the precise mechanism shown, as it is obviously ca able of much variation without departing rom the spirit of my invention.

I claim 1. In a pneumatically actuated valve a valve for closing one of such openings, and

mechanism for actuating such valve.

3. A vpneumatic having a controlling duct or connection, two bleed holes, and means 'for opening and closing one of them.

4,. A pneumatic having a controlling duct or connection, two bleed holes, means for opening and closing one of them, said means comprising a movable valve, and connections for actuating the valve from a distance.

5. In combination with a tracker, a tracker duct, and a pneumatic connected with said duct, said duct having two bleed holes and a valve for one of them. 1 6. In combinationwith a tracker, a tracker duct, and a pneumatic connected with said duct, said duct having two bleed holes and a valve for one of them, and mechanical connections from the vicinity of the tracker for opening and .closing the bleed hole valve.

7. In combination, a tracker having two sets of tracker ducts, a pneumatic connected with one .duct of each set,- and provided with two bleed holes, and means for openingand closin one of them. p p

8. Ih combination, a tracker having two sets of tracker duct-s, a pneumatic connected with one duct of each set, and rovided With two bleed holes, and a'valve tor one of the said bleed holes having connections for actuating it to change the amount of bleed at will. i

9. A pneumatic having a controlling duct or pneumatic connection, one or more bleed 

